jqno#201 Fixes bug in interplay with abstract methods and lazy initia…

…lization
akhalikov · Jul 29, 2018 · 29954fe · 29954fe
1 parent c69caa0
commit 29954fe
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Showing 3 changed files with 69 additions and 3 deletions.
diff --git a/src/main/java/nl/jqno/equalsverifier/internal/checkers/HierarchyChecker.java b/src/main/java/nl/jqno/equalsverifier/internal/checkers/HierarchyChecker.java
@@ -85,8 +85,8 @@ private void safelyCheckSuperProperties(ObjectAccessor<T> referenceAccessor) {
         try {
             checkSuperProperties(reference, equalSuper, shallowCopy);
         }
-        catch (AbstractMethodError ignored) {
-            // In this case, we'll assume all super properties hold.
+        catch (AbstractMethodError | NullPointerException ignored) {
+            // In these cases, we'll assume all super properties hold.
             // The problems we test for, can never occur anyway if you can't instantiate a super instance.
         }
     }

diff --git a/src/main/java/nl/jqno/equalsverifier/internal/checkers/NullChecker.java b/src/main/java/nl/jqno/equalsverifier/internal/checkers/NullChecker.java
@@ -91,15 +91,25 @@ private void handle(String testedMethodName, Field field, Runnable r) {
             catch (NullPointerException e) {
                 npeThrown(testedMethodName, field, e);
             }
+            catch (AbstractMethodError e) {
+                abstractMethodErrorThrown(testedMethodName, field, e);
+            }
             catch (Exception e) {
                 exceptionThrown(testedMethodName, field, e);
             }
         }
 
-        private void npeThrown(String method, Field field, Exception e) {
+        private void npeThrown(String method, Field field, NullPointerException e) {
             fail(Formatter.of("Non-nullity: %% throws NullPointerException on field %%.", method, field.getName()), e);
         }
 
+        private void abstractMethodErrorThrown(String method, Field field, AbstractMethodError e) {
+            fail(Formatter.of(
+                    "Abstract delegation: %% throws AbstractMethodError when field %% is null.\n" +
+                    "Suppress Warning.NULL_FIELDS to disable this check.",
+                    method, field.getName()), e);
+        }
+
         private void exceptionThrown(String method, Field field, Exception e) {
             fail(Formatter.of("%% throws %% when field %% is null.", method, e.getClass().getSimpleName(), field.getName()), e);
         }

diff --git a/src/test/java/nl/jqno/equalsverifier/integration/inheritance/AbstractHierarchyTest.java b/src/test/java/nl/jqno/equalsverifier/integration/inheritance/AbstractHierarchyTest.java
@@ -36,6 +36,23 @@ public void succeed_whenEqualsThrowsNull_givenClassIsAbstractAndWarningIsSuppres
                 .verify();
     }
 
+    @Test
+    public void fail_whenAbstractImplementationThrowsNpe() {
+        expectFailure("Abstract delegation: equals throws AbstractMethodError when field object is null");
+        EqualsVerifier.forClass(NullThrowingLazyObjectContainer.class)
+                .suppress(Warning.NONFINAL_FIELDS)
+                .withIgnoredFields("objectFactory")
+                .verify();
+    }
+
+    @Test
+    public void succeed_whenAbstractImplementationThrowsNpe_givenWarningIsSuppressed() {
+        EqualsVerifier.forClass(NullThrowingLazyObjectContainer.class)
+                .suppress(Warning.NULL_FIELDS, Warning.NONFINAL_FIELDS)
+                .withIgnoredFields("objectFactory")
+                .verify();
+    }
+
     abstract static class AbstractFinalMethodsPoint {
         private final int x;
         private final int y;
@@ -113,4 +130,43 @@ public final boolean equals(Object obj) {
 
         @Override public final int hashCode() { return defaultHashCode(this); }
     }
+
+    interface Supplier<T> {
+        T get();
+    }
+
+    abstract static class AbstractLazyObjectContainer {
+        private Object object;
+
+        private Object getObject() {
+            if (object == null) {
+                object = createObject();
+            }
+            return object;
+        }
+
+        protected abstract Object createObject();
+
+        @Override
+        public boolean equals(final Object obj) {
+            if (!(obj instanceof AbstractLazyObjectContainer)) {
+                return false;
+            }
+            AbstractLazyObjectContainer other = (AbstractLazyObjectContainer)obj;
+            return getObject().equals(other.getObject());
+        }
+
+        @Override public int hashCode() { return getObject().hashCode(); }
+    }
+
+    static final class NullThrowingLazyObjectContainer extends AbstractLazyObjectContainer {
+        private final Supplier<Object> objectFactory;
+
+        protected NullThrowingLazyObjectContainer(Supplier<Object> flourFactory) { this.objectFactory = flourFactory; }
+
+        @Override
+        protected Object createObject() {
+            return objectFactory.get();
+        }
+    }
 }